'Bleachorexia': Dentist Warns About Dangers of Overbleaching Teeth

— -- Mia St. John is obsessed with getting whiter, cleaner teeth.

The five-time World Boxing Council champion in the super welterweight division said her quest for pearly whites grew so extreme she was brushing and bleaching constantly until her dentist intervened.

“He said my teeth could basically turn to mush just because I was destroying the enamel,” she said.

The obsession for megawatt smiles and using over-the-counter whiteners is now leading to what many dentists are calling “bleachorexia.”

Laurence Rifkin, a cosmetic dentist in Los Angeles, said overbleaching is common and can lead to receding gums and oversensitivity. Too much bleaching can also have a reverse effect, leaving teeth with a darker appearance, he also said.

“Too much of a good thing is really bad,” he said.

In extreme cases, Rifkin said, he’s even heard of people rubbing Clorox bleach on their teeth.

“It's good for surfaces and cleaning, but not in the mouth or even on the skin. It's very caustic,” he said.

The American Dental Association recommends that people who choose to use a bleaching product do so only after consultation with a dentist.

"The ADA recommends that if you choose to use a bleaching product, you should only do so after consultation with a dentist. This is especially important for patients with many fillings, crowns, and extremely dark stains. A thorough oral examination, performed by a licensed dentist, is essential to determine if bleaching is an appropriate course of treatment. The dentist and patient together can determine the most appropriate treatment. The dentist may then advise the patient and supervise the use of bleaching agents within the context of a comprehensive, appropriately sequenced treatment plan ... Patients should be cautioned that not enough information is available to support unsupervised long-term and/or repeated use of bleaching products,” the ADA told ABC News.

Rifkin said overbleaching can cause irreversible damage.

“Once the enamel has been chemically eroded away, then it’s gone, it’s gone forever,” he said.

St. John got the message.

“To say that I'm no longer obsessed with my teeth would be a lie, but I have it under control now,” she said.